THE sums haven't been done yet, but back-of-an-envelope figures suggest the Kalajzic family, Cadoux, are in the black.

And there's agreement from father and son combination Michael and Shaun that it was a good idea to buy a factory-fitted MDC app from Harvey manufacturer Roesner with the Marshall 916T spreader, sold by Boekeman Machinery, Wongan Hills.

With 5500 hectares of spreading done this year, designated spokesman Shaun has given the app the thumbs up.

"We got a new spreader at the start of the year because we wanted more capacity and with the 916T we can get up to 20 tonnes of a 2:1 lime and gypsum mix, spreading at a rate of between 1.2 tonnes per hectare and 1.5t/ha," he said.

"Our 20-year-old spreader could only handle 8t so this has given us quite a bit of a productivity lift plus we have the bonus of the app to do variable rate application.

"We've spread sulphate of ammonia, lime, gypsum, urea and compost and the machine still looks new."

With their own gypsum supply, the plan is to focus on a soil amelioration program involving gypsum and lime, with the gypsum breaking down the clays and carrying the lime through.

"It's arguably the most cost-efficient way of doing it," Shaun said.

The MDC app is employed for variable rate spreading via belt drive rather than employing the variable actuator on the rear door.

"We just find the belt responds well, with speed changes that are almost instantaneous," Shaun said.

"You just have to watch the sprocket settings and once you've got it right and entered the settings on the computer, it's almost a set-and-forget system.

"When I calibrate different products I weigh three times before saving and it's pretty much like calibrating your air seeder.

"We use the John Deere GreenStar 2600 display to calibrate product rates integrated with yield maps."

The app is Bluetooth-enabled with the receiver mounted on the front outside wall of the spreader and a power cable to the battery plugging in on the back of the tractor. It can be employed on any smart tablet or iPhone.

"The app is easy to understand and operate and with the weigh scales it makes calibration so much easier," Shaun said.

Load cells - mounted on the hitch and left and right axles - monitor the amount of material in the hopper, and help the user adjust calibration when fertiliser densities change.

"In operation the app allows you to see exactly what is happening regarding rates and bin status in real time along with paddock location.

"And, of course, it's all recorded so if for any reason you have to stop, you can resume at exactly where you left off."

The spreader itself ticks the boxes, emphasised this year by Shaun's first attempt at spreading 35 kilograms per hectare of urea over early flowering canola.

"We did it in wettish weather, covered 420ha in eight hours, spreading at 36 metres (120ft), travelling about 25 kilometres per hour and you couldn't see the wheel marks," Shaun said.

"The spreader has BPW tandem axles and walking beam configuration for good steering which is an absolute must."

Shaun says the 916T is only limited by the quality of the product.

"We do a lot of sulphate of ammonia spreading and the first lot we got this year we were able to spread at about 20 metres (66ft) at rates between 80 and100kg/ha," he said.

"But a second batch was too dusty and powdery and we had to cut back to spreading at about 14m (nearly 46ft). "

With lime and gypsum, Shaun said he consistently achieved 12m (40ft), even in windy conditions.

"The tandem walking beam axles give you a great ride which makes the job a bit more pleasant.

"It just tracks well which means less scrubbing on turns and you do notice the lack of jerking when you're fully loaded and travelling at 25km/h or empty at 40km/h," he said.

"It's interesting that somebody made the observation there was no urea falling off the discs when we were on the road."

The decision to buy the 916T with the MDC app was based on the build quality of the machine, local support from Boekeman Machinery and Roesner.

"We like supporting local and being a WA manufacturer, it's easy to communicate with the company when there's an issue and you do get a quick response," Shaun said.

"To be honest I was expecting teething problems with the load cells but we have had no issues on that score.

"The only issue I have is inputting weights into the rate controller but the company says it is working on that which is great."

Company director Matt Roesner's thinking when he developed the MDC app was that Bluetooth was being used for everyday uses and could easily be adapted for use to make things easier and more cost efficient for farmers.

Roesner has partnered with SoftWaring Solutions, the developers of InMotion, a flexible cloud-based platform, for managing geospatial and temporal data (variation of application rate over time along with data on spinner speeds and door openings).

The InMotion web app, in private beta testing (tested in the "real world" with "real customers" and integrating customer input), tracks the spreader in the field and provides a map of as-applied fertiliser updated in real time.

"When connected to a mobile network the monitoring page shows a geo-referenced map of the machine's position and its previous path in the paddock while at the same time syncing data to the InMotion cloud platform," Mr Roesner said.

"The system will still operate if you lose Bluetooth connection from radio interference but that's a rare occurrence and in any event, you press the refresh button and all logged data is there for you because the spreader will keep doing what's its told.

"The core of the app remains the accurate calibration tools which are based on years of empirical tests with different fertilisers."